WO2012090605A1

WO2012090605A1 - Bearing cap and bearing cap composite

Info

Publication number: WO2012090605A1
Application number: PCT/JP2011/076193
Authority: WO
Inventors: 裕聡星川; 和貴有馬
Original assignee: 日産自動車株式会社
Priority date: 2010-12-27
Filing date: 2011-11-14
Publication date: 2012-07-05
Also published as: JP5884266B2; CN103154538B; US20130163906A1; CN103154538A; EP2660485A1; EP2660485A4; US9011012B2; JP2012137151A

Abstract

The present invention relates to a bearing cap (11) for rotatably supporting a crankshaft by being fastened to a bulkhead (2) of a cylinder block (1). A pair of protrusions (25, 26) is formed on a pair of side surfaces (33, 34) respectively, which enlarge a joint surface (12) with the bulkhead (2) in the traverse direction of the crankshaft. By providing a pair of reinforcing sections (35, 36), which protrude in the traverse direction of the crankshaft from the pair of side surfaces (33, 34) and have a smaller projection amount than the pair of the protrusions (25, 26), at a side of a top face (19) from the pair of protrusions (25, 26), it is possible to reduce a stress to be generated by the crankshaft in a junctional region of the bearing cap (11) and the bulkhead (2) during the driving of an internal combustion engine without impairing the rigidity of the bearing cap (11).

Description

Bearing cap and bearing cap composite

The present invention relates to a bearing cap for supporting a crankshaft of an internal combustion engine and the like, and a bearing cap complex such as a ladder frame including the bearing cap as a constituent element.

The crankshaft of an internal combustion engine is supported by, for example, a bulkhead formed in a cylinder block and a bearing cap fixed to the bulkhead.

JP93-062216U, issued by the Japan Patent Office in 1991, proposes a bearing structure in which a bearing cap is fitted into a recess formed in a bulkhead and fixed to the bulkhead with bolts. This bearing structure forms chamfers at both ends of the bearing cap with respect to the transverse direction of the crankshaft so that the bearing cap does not cause stress concentration at both ends of the recess of the bulkhead as the internal combustion engine is operated. Grooves are formed at both corners of the opposing recess.

By providing chamfered portions at both ends of the bearing cap, a space is formed between the chamfered portion and the groove, so stress concentration on this portion can be avoided. On the other hand, since the contact area between the bearing cap and the bulkhead is reduced by the chamfered portion, it is unavoidable that the stress generated by the crankshaft at the joint between the bearing cap and the bulkhead during the operation of the internal combustion engine is increased overall. Absent.

Therefore, the object of the present invention is to reduce the stress generated at the joint between the bearing cap and the bulkhead by the crankshaft during operation of the internal combustion engine without impairing the rigidity of the bearing cap.

In order to achieve the above object, the present invention is directed to a bearing cap that is fixed to a bulkhead of a cylinder block with a bolt and rotatably supports a crankshaft. The bearing cap includes a joint surface with the bulkhead, a top surface located on the opposite side of the joint surface, and a pair of side surfaces connecting the joint surface and the top surface. The bearing cap further includes a pair of projecting portions formed on the pair of side surfaces, each having a joint surface extending in the transverse direction of the crankshaft, and a crankshaft from the pair of side surfaces located on the top surface side of the pair of projecting portions. And a pair of reinforcing portions that protrude in the transverse direction and have a smaller protruding amount than the overhanging portion.

DETAILED DESCRIPTION Details and other features and advantages of the present invention are described in the following description of the specification and shown in the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a cylinder block of an internal combustion engine showing a state in which a bearing cap according to a first embodiment of the present invention is attached to a bulkhead. FIG. 2 is a front view of the bearing cap. FIG. 3 is a bottom view of the bearing cap as viewed from below. FIG. 4 is a schematic cross-sectional view of a cylinder block of an internal combustion engine showing a state in which a bearing cap composite comprising a bearing cap and a ladder frame according to a second embodiment of the present invention is attached to a bulkhead. FIG. 5 is a plan view of a bearing cap composite according to a second embodiment of the present invention. FIG. 6 is a front view of a bearing cap according to a second embodiment of the present invention. FIG. 7 is a bottom view of the bearing cap according to the second embodiment of the present invention viewed from below. FIG. 8 is a schematic cross-sectional view of a cylinder block of an internal combustion engine showing a state in which a bearing cap composite according to a third embodiment of the present invention is attached to a bulkhead. FIG. 9 is a plan view of a bearing cap composite according to a third embodiment of the present invention. FIG. 10 is a front view of a bearing cap according to a third embodiment of the present invention. FIG. 11 is a bottom view of a bearing cap according to a third embodiment of the present invention viewed from below. FIG. 12 is a diagram for comparing the stresses exerted on the joint surface of the bearing cap by the bearing cap composite according to the second and third embodiments of the present invention and the conventional bearing cap structure.

Fig. Of the drawing. Referring to FIG. 1, a bearing for supporting a crankshaft of a reciprocating internal combustion engine includes a bulkhead 2 formed in a cylinder block 1 of the internal combustion engine, and a bearing cap 11 fixed to the bulkhead 2 with

bolts

52 and 53. Consists of.

The body of the cylinder block 1 including the bulkhead 2 is made of an aluminum alloy or aluminum material that is lighter than an iron-based material for weight reduction. The bulkhead 2 functions as a partition wall for dividing each cylinder into a cylinder block 1.

In the operating state of the internal combustion engine, the bulkhead 2 constitutes a vertical wall surface. The lower end 3 of the bulkhead 2 forms a horizontal straight line, and a semicircular cutout 4 is formed at the approximate center of the lower end 3. The cylinder block 1 is, for example, a cylinder block for an in-line multi-cylinder engine in which a plurality of cylinders are arranged in a row.

The bearing cap 11 made of an iron-based material such as cast iron is fixed to the bulkhead 2. The bearing cap 11 has a rectangular thick plate shape. A semicircular cutout 13 corresponding to the cutout 4 is formed on the joint surface 12 of the bearing cap 11 with the bulkhead 2.

The bearing cap 11 is fixed to the lower end 3 of the bulkhead 2 at a position where the

notches

4 and 13 are opposed to form a circular bearing hole 51. The crankshaft is rotatably supported via a journal bearing mounted in the bearing hole 51 and lubricating oil supplied to the journal bearing.

The bearing cap 11 is fixed to the bulkhead 2 by a pair of

bolts

52 and 53. For this purpose,

bolt insertion holes

14 and 15 are formed on both sides of the notch 13 of the bearing cap 11. Further,

screw holes

5 and 6 into which the

bolts

52 and 53 are screwed are formed in the bulk head 2.

The bearing cap 11 is fixed to the lower end 3 of the bulkhead 2 by passing the bolt 52 through the bolt insertion hole 14 and tightening it into the screw hole 5 and passing the bolt 53 through the bolt insertion hole 15 and tightening it into the screw hole 6. .

The joint surface 12 of the bearing cap 11 with the bulkhead 2, the top surface 19 opposite to the joint surface 12, that is, the lower surface in the figure, and the

side surfaces

33 and 34 that connect the joint surface 12 and the top surface 19. Have. The head 52a of the bolt 52 and the head 53a of the bolt 53 abut on the top surface 19 from below.

FIG. 2, the bearing cap 11 is composed of a half-cut cylindrical portion 21 that forms the notch 13 and a base-like portion 31 that continues below the cylindrical portion 21, and is formed symmetrically as a whole. Yes.

The cylindrical portion 21 is formed with

overhang portions

25 and 26 that protrude from the

side surfaces

33 and 34 in the horizontal direction and perpendicular to the crankshaft, that is, in the left and right directions in the figure. The dimensions of the joint surface 12 corresponding to the

overhang portions

25 and 26 in the crankshaft axial direction are the same as other portions of the joint surface 12. The

overhang portions

25 and 26 expand the joint surface 12 of the bearing cap 11 to the bulkhead 2 on both sides in the horizontal direction, and increase the joint area between the bearing cap 11 and the bulkhead 2.

The enlargement of the joint area between the bearing cap 11 and the bulkhead 2 reduces the contact surface pressure between them, and brings about the effect that the bearing cap 11 reduces the stress generated in the bulkhead 2.

Further, reinforcing

portions

36 and 37 are formed on the base portion 31 located on the top surface 19 side of the

overhang portions

25 and 26. The reinforcing

portions

36 and 37 project from the

side surfaces

33 and 34 in the same direction as the projecting

portions

25 and 26. The overhang amounts of the reinforcing

portions

36 and 37 are set smaller than the overhang amounts of the

overhang portions

25 and 26. Here, the amount of overhang means the amount of protrusion from the

side surfaces

33 and 34 in the horizontal direction. The reinforcing

portions

36 and 37 have a role of increasing the rigidity of the

overhang portions

25 and 26.

The overhanging portion 25 located on the left side of the figure decreases in thickness toward the tip, that is, away from the crankshaft. The overhanging portion 26 located on the right side of the figure also decreases in thickness toward the distal end, that is, away from the crankshaft. As the thickness decreases, the lower surfaces of the

overhang portions

25 and 26 are inclined. This is because the thickness of the

overhang portions

25 and 26 is changed in this way to suppress an increase in the weight of the bearing cap 11 due to the formation of the

overhang portions

25 and 26. The reinforcing

portions

36 and 37 constitute a part of the base portion 31 and are coupled to the inclined lower surfaces of the

overhang portions

25 and 26.

Thus, by providing the reinforcing

portions

36 and 37 on the

side surfaces

33 and 34 of the bearing cap 11, the

overhang portions

25 and 26 having a large overhang amount can maintain sufficient rigidity.

FIG. Referring to FIG. 3, auxiliary reinforcing

portions

81 and 82 projecting from the side surfaces 33 and 34 in the left and right directions in the figure are formed on the base portion 31 of the bearing cap 11 so as to enlarge the top surface 19. The auxiliary reinforcing

portions

81 and 82 also serve to increase the rigidity of the bearing cap 11.

In this way, the bearing cap 11 reduces the stress generated in the bulkhead 2 from the crankshaft through the bearing cap 11 by the

overhang portions

25 and 26 projecting horizontally from the side surfaces 33 and 34, while the side surface 33. Reinforcing

portions

36 and 37 projecting from the projecting

portions

34 and 34 with a smaller projecting amount in the same direction support the projecting

portions

25 and 26 and ensure the rigidity of the bearing cap 11.

Therefore, according to the bearing cap 11, it is possible to reduce the stress generated in the bearing cap 11 and the bulkhead 2 by the crankshaft during operation of the internal combustion engine.

Fig. A second embodiment of the present invention will be described with reference to 4-7.

This embodiment relates to a bearing cap composite. The bearing cap composite includes a bearing cap 11 and a ladder frame 71 as a bearing cap holding member. The ladder frame 71 is formed of a metal material such as an aluminum alloy that is lighter than the bearing cap 11 made of an iron-based material and has a lower melting point than the bearing cap 11. The bearing cap 11 is cast into the ladder frame 71 to constitute an integral bearing cap composite.

FIG. Referring to FIG. 5, the ladder frame 71 has a ladder shape in which both ends of five cross members 74 arranged in parallel are coupled by a pair of

beam members

75 and 76 to be applied to an in-line four-cylinder internal combustion engine. The crosspiece member 74 is disposed so as to be located immediately below the bulkhead formed in the cylinder block. The bearing cap complex having the ladder frame 71 configured as described above is obtained by changing the number of crosspiece members 74. The present invention is not limited to an in-line four-cylinder internal combustion engine, and can be applied to an internal combustion engine having an arbitrary number of cylinders.

FIG. Referring to FIG. 4, the bearing cap 11 is cast between

cap extensions

72 and 73 which are part of a crosspiece member 74 located on the outer side in the horizontal direction. The

cap extensions

72 and 73 are made of an aluminum alloy in the same manner as other portions of the ladder frame 71. By casting the bearing cap 11 between the

cap extensions

72 and 73, an integral thick plate-like cross member 74 is formed.

Again FIG. 5, the pair of

girder members

75 and 76 are also formed of an aluminum alloy. Five bearing caps 11 are cast in the ladder frame 71.

Fig. Referring to FIGS. 6 and 7, unlike the first embodiment, the bearing cap 11 does not include the auxiliary reinforcing

portions

81 and 82. This is because the

cap extensions

72 and 73 coupled to the left and right sides of the bearing cap 11 provide a rigidity enhancing action equal to or greater than that of the auxiliary reinforcing

parts

81 and 82.

Similarly to the first embodiment, the bearing cap 11 according to this embodiment also extends from the side surfaces 33 and 34 to the cylindrical portion 21 in a direction that is horizontal and orthogonal to the crankshaft, that is, a protruding portion 25 that protrudes in the left and right directions in the figure. And 26 are formed. Reinforcing

portions

overhang portions

25 and 26. The overhang amounts of the reinforcing

portions

36 and 37 are set smaller than the overhang amounts of the

overhang portions

25 and 26.

In this embodiment, the shapes of the reinforcing

portions

36 and 37 are slightly different from those of the first embodiment. This will be described later.

Thus, the reason why the bearing cap 11 made of an iron-based material is cast into the aluminum alloy ladder frame 71 is to reduce the weight of the bearing cap composite. That is, the weight of the bearing cap composite can be reduced as compared with the case where the ladder frame 71 is made of the same iron-based material as the bearing cap 11.

When casting the bearing cap 11 into the ladder frame 71, if the joint surface between the bearing cap 11 made of ferrous material and the

cap extension portions

72 and 73 of the ladder frame 71 made of aluminum alloy is flat, they are brought into close contact with each other. Difficult to hold. On the other hand, if the bearing cap 11 and the

cap extensions

72 and 73 are not in close contact with each other, the rigidity of the bearing cap composite is lowered, and the bearing cap composite cannot maintain sufficient strength.

In this embodiment, by providing the

overhang portions

25 and 26 and the reinforcing

portions

36 and 37, the adhesion between the bearing cap 11 and the

cap extension portions

72 and 73 is enhanced. The enhancement of the adhesion between the bearing cap 11 and the

cap extensions

72 and 73 brings about an increase in the rigidity of the entire ladder frame 71.

The load in the rotation direction centering on the bearing hole 51 acts on the bearing cap 11 according to the rotation of the crankshaft. Since the adhesion between the bearing cap 11 and the

cap extension portions

72 and 73 is enhanced by the

overhang portions

25 and 26 and the

reinforcement portions

36 and 37, the load in the rotational direction can be supported by the

cap extension portions

72 and 73. It becomes possible.

In order to hold the bearing cap 11 in close contact with the

cap extensions

72 and 73, the bearing cap 11 according to this embodiment has two projecting portions 43 projecting on the side surface 33 below the reinforcing portion 36 in the same direction as the reinforcing portion 36. And 45. Similarly, two projecting

portions

44 and 46 projecting in the same direction as the reinforcing portion 37 are provided on the side surface 34 below the reinforcing portion 37.

Preferably, the

protrusions

43 and 44 have the same shape and are arranged at equal intervals in the vertical direction from the reinforcing portion 36. Similarly, the

protrusions

44 and 46 have the same shape and are arranged at equal intervals from the reinforcing portion 37 in the vertical direction.

Prior to casting the ladder frame 71 using the aluminum alloy material, the

protrusions

43 and 45 bite into the cap extension 72 of the ladder plate 71 by arranging the bearing cap 11 in the mold, and the cap extension. With the projecting

portions

44 and 46 biting into the portion 73, an integral bearing cap composite is formed. The

protrusions

43 and 45 that bite into the cap extension 72 increase the contact area between the bearing cap 11 and the cap extension 72, and the

protrusions

44 and 46 that bite into the cap extension 73 become the bearing cap 11 and the cap extension. The contact area of the part 73 is increased. As a result, the bearing cap 11 is firmly attached to the ladder frame 71.

In this embodiment, the reinforcing portion 36 provided on the side surface 33 of the bearing cap 11 and the reinforcing portion 37 provided on the side surface 34 are set to dimensions different from those of the first embodiment. That is, in this embodiment, the dimensions of the reinforcing

portions

36 and 37 in the vertical direction or the vertical direction in the figure are set smaller than the reinforcing

portions

36 and 37 of the first embodiment. Further, a concave portion 38 that is recessed in the horizontal direction is formed between the reinforcing portion 36 and the protruding portion 25, and a concave portion 39 that is recessed in the horizontal direction is formed between the reinforcing portion 37 and the protruding portion 26.

Furthermore, in this embodiment, the shape formed by the reinforcing portion 36 and the recessed portion 38 is made similar to the protruding

portions

43 and 45. Similarly, the shape formed by the reinforcing portion 37 and the recessed portion 39 is made similar to the protruding

portions

44 and 46. Such similarity in the shapes of the reinforcing

portions

36 and 37 and the protruding portions 43 to 46 indicates that the adhesion between the bearing cap 11 and the

cap extension portions

72 and 73 which are two members of different materials is as shown in FIG. 4 is preferable in order to equalize the vertical direction.

On the other hand, if the size of the reinforcing

portions

36 and 37 in the vertical direction or the vertical direction in the figure is made smaller than that of the reinforcing

portions

36 and 37 of the first embodiment, the rigidity of the bearing cap 11 itself is lowered. However, when considered as a bearing cap composite, the

cap extensions

72 and 73 compensate for the decrease in rigidity of the bearing cap 11, and the rigidity as the bearing cap composite does not decrease.

According to this bearing cap composite, the joint area between the bearing cap 11 of the iron-based member and the

cap extensions

72 and 73 of the aluminum alloy is expanded, and the adhesion between two members of different materials is improved. As a result, the bearing cap composite including the bearing cap 11 of the ironing member and the aluminum alloy ladder frame 71 in which the bearing cap 11 is cast has high adhesion between the bearing cap 11 and the

cap extensions

72 and 73. In general, high rigidity can be provided.

Further, since the reinforcing

portions

36 and 37 have substantially the same shape as the protruding portions 43-46 by forming the

concave portions

38 and 39, the degree of close contact between the bearing cap 11 and the

cap extension portions

72 and 73 in the vertical direction is made uniform. be able to.

Further, the reinforcing portion 36 and the protruding

portions

43 and 44 are arranged along the side surface 33 in FIG. 4, the reinforcing portion 37 and the projecting

portions

44 and 46 are arranged at substantially equal intervals in the vertical direction along the side surface 34, so that the bearing cap 11 and the

cap extension portions

72 and 73 are The degree of adhesion in the vertical direction can be made even more uniform.

The

concave portions

38 and 39 increase the joint area between the bearing cap 11 and the

cap extension portions

72 and 73. This increase in the bonding area also contributes to improving the adhesion between the bearing cap 11 and the

cap extensions

72 and 73, which are two members of different materials.

Fig. A third embodiment of the present invention will be described with reference to 8-11.

Fig. Referring to FIGS. 8 and 9, as in the second embodiment, in this embodiment, a bearing cap 11 made of an iron-based material is cast into a ladder frame 71 made of, for example, an aluminum alloy metal warehouse material that is lighter and has a lower melting point than the bearing cap 11. Targeting bearing cap composites.

Fig. Referring to FIGS. 10 and 11, the bearing cap 11 is provided with

overhangs

25 and 26 similar to those of the first embodiment. Reinforcing

portions

overhang portions

25 and 26. The reinforcing

portions

36 and 37 project from the side surfaces 33 and 34 in the same direction as the projecting

portions

25 and 26. The overhang amounts of the reinforcing

portions

36 and 37 are set smaller than the overhang amounts of the

overhang portions

25 and 26. The amount of overhang means the amount of protrusion in the horizontal direction from the side surfaces 33 and 34. The reinforcing

portions

36 and 37 have a role of increasing the rigidity of the

overhang portions

25 and 26.

However, in this embodiment, the vertical lengths of the reinforcing

portions

36 and 37 are set shorter than those in the first embodiment. Further, the

recesses

38 and 39 of the second embodiment are not formed.

The bearing cap 11 according to this embodiment corresponds to a deformation of the bearing cap 11 according to the second embodiment. That is, in this embodiment, the side surface 33 of the bearing cap 11 is provided with a protruding portion 47 that protrudes outward in the horizontal direction. A protrusion 48 is provided on the side surface 34 of the bearing cap 11. By limiting the

protrusions

47 and 48 provided on the side surfaces 33 and 34 to one each in this way, the bearing cap 11 can be easily manufactured as compared with the second embodiment.

In order to secure a bonding area between the bearing cap 11 and the

cap extension portions

72 and 73 by the one

protrusion portions

47 and 48, the

protrusion portions

47 and 48 protrude more outward in the horizontal direction than the reinforcing

portions

36 and 37. . In other words, the amount of protrusion of the projecting

portions

47 and 48 is set larger than that of the reinforcing

portions

36 and 37. The

protrusions

47 and 48 are preferably provided at the center of the bearing cap 11 in the vertical direction. This is because if the

protrusions

47 and 48 are provided at positions deviated upward or downward from the central portion, the degree of adhesion between the bearing cap 11 and the

cap extension portions

72 and 73 is uneven in the vertical direction.

However, the reinforcing

portions

36 and 37 with a small amount of protrusion outward in the horizontal direction also contribute to some extent in increasing the joint area with the

cap extension portions

72 and 73 of the bearing cap 11. Taking this contribution into account, disposing the

protrusions

47 and 48 slightly below the center of the bearing cap 11 in the up-and-down direction can increase the degree of adhesion between the bearing cap 11 and the

cap extensions

72 and 73 in the up-and-down direction. Is preferable for averaging.

This embodiment can provide the same effects as those of the second embodiment.

In this embodiment, since only one

protrusion

47 and 48 is provided on each of the side surfaces 33 and 34 of the bearing cap 11, a plurality of 43-46 protrusions are provided on the side surfaces 33 and 34. In comparison, the processing of the bearing cap 11 is facilitated.

FIG. Referring to FIG. 12, the stresses caused by the bearing cap composite according to the second and third embodiments of the present invention and the conventional bearing cap structure on the joint surface between the bearing cap and the bulkhead are compared.

During operation of the internal combustion engine, the tightening stress by the

bolts

52 and 53 acts on the joint surface 12 of the bearing cap 11 with the bulkhead 2. In addition, thermal stress and residual stress act. FIG. The “average stress” on the horizontal axis of the twelve diagrams means the average stress when the sum of these stresses acts on the joint surface 12 during operation of the internal combustion engine.

Also, during operation of the 4-stroke cycle engine, a fluctuating stress that fluctuates in a manner that approximates a sine curve acts on the joint surface 12. “Variable piece amplitude stress” on the horizontal axis of the diagram means half of the amplitude of this variable stress.

∙ The lower-right line shown in the diagram represents the boundary line that can maintain the durability of the cylinder block 1. That is, if the operating state of the internal combustion engine is above the boundary line, the durability of the cylinder block 1 cannot be maintained. An area labeled “NG” on the diagram corresponds to this condition. If the operating state of the internal combustion engine is below the boundary line, the durability of the cylinder block 1 can be maintained. An area labeled “OK” on the diagram corresponds to this condition.

In an internal combustion engine that employs a conventional bearing cap, the bearing cap composite according to the second or third embodiment of the present invention is employed even if the operating state is above the boundary line as indicated by the black circles. Therefore, it is expected that the driving state will be below the boundary line as shown by the squares and diamonds in the figure. Therefore, according to the present invention, the durability of the cylinder block 1 can be enhanced.

Regarding the above description, the contents of Japanese Patent Application No. 2010-290315, filed on December 27, 2010, are incorporated herein by reference.

Although the present invention has been described through some specific embodiments, the present invention is not limited to the above embodiments. Those skilled in the art can make various modifications or changes to these embodiments within the scope of the claims.

In the second and third embodiments described above, a bearing cap complex is formed by casting the bearing cap 11 into a bearing holding member made of a metal material that is lighter and has a lower melting point than the bearing cap 11. The bearing holding member is composed of a plurality of crosspiece members 74 and a ladder frame 71 including

girder members

75 and 76 that connect both ends of the crosspiece members 74. And the crosspiece member 74 is comprised by the

cap extension parts

72 and 73 and the bearing cap 11 cast between these.

However, the bearing cap holding member is not limited to the ladder frame 71, and various configurations are possible. For example, a crosspiece member 74 in which the bearing cap 11 is cast between the

cap extension portions

72 and 73 can be used as the bearing holding member. In this case, the crosspiece 74 is independent for each bulkhead 2 and is individually fixed to the bulkhead 2.

As described above, the bearing cap and the bearing cap composite according to the present invention reduce the stress generated at the joint between the bulkhead and the bearing cap of the internal combustion engine. Therefore, for example, it is expected to bring about a favorable effect for improving the durability of an automobile engine.

Claims

In a bearing cap (11) fixed to the bulkhead (2) of the cylinder block (1) with bolts (52, 53) and rotatably supporting the crankshaft:
A joint surface (12) with the bulkhead (2);
A top surface (19) located opposite the joining surface (12);
A pair of side surfaces (33, 34) connecting the joining surface (12) and the top surface (19);
A pair of overhanging portions (25, 26) projecting from the pair of side surfaces (33, 34), respectively, expanding the joining surface (12) in the transverse direction of the crankshaft;
Projecting from the pair of overhanging portions (25, 26) which are located on the top surface (19) side from the pair of overhanging portions (25, 26) and project from the pair of side surfaces (33, 34) in the transverse direction of the crankshaft. A pair of small reinforcements (36, 37);
Is provided.
Projecting in the transverse direction of the crankshaft from the pair of side surfaces (33, 34) independently of the pair of reinforcement portions (36, 37) on the top surface (19) side of the pair of reinforcement portions (36, 37), The bearing cap (101) according to claim 1, further comprising a pair of projecting portions (47, 48) having a projecting amount smaller than that of the pair of projecting portions (25, 26).
The bearing cap (101) according to claim 2, wherein the pair of projecting portions (47, 48) are provided at the center of both side surfaces (33, 34) of the bearing cap (11).
The bearing cap according to claim 2 or 3, wherein each of the pair of reinforcing portions includes a recess (38, 39).
Projecting in the transverse direction of the crankshaft from the pair of side surfaces (33, 34) independently of the pair of reinforcement portions (36, 37) on the top surface (19) side of the pair of reinforcement portions (36, 37), The bearing cap according to claim 1, comprising a plurality of pairs of protrusions (43-46) arranged at equal intervals and having a smaller protrusion amount than the pair of overhang portions (25, 26).
In a bearing cap complex fixed to the bulkhead (2) of the cylinder block (1) with bolts (52, 53) and rotatably supporting the crankshaft:
A joint surface (12) with the bulkhead (1);
A top surface (19) located opposite the joining surface (12);
A pair of side surfaces (33, 34) connecting the joining surface (12) and the top surface (19);
A pair of overhanging portions (25, 26) formed on the pair of side surfaces (33, 34), respectively, extending the joining surface (12) in the transverse direction of the crankshaft;
Projecting from the pair of overhanging portions (25, 26) which are located on the top surface (19) side from the pair of overhanging portions (25, 26) and project from the pair of side surfaces (33, 34) in the transverse direction of the crankshaft. A pair of small reinforcements (35, 36);
A bearing cap (11) comprising:
And the bearing cap holding member by metal material having low light and and melting point than the bearing cap (11),
Bearing cap composite comprising.
A plurality of bearing caps (11) spaced apart in the axial direction of the crankshaft;
A crosspiece member (72, 73) coupled to each bearing cap (11) and projecting from each bearing cap (11) to both sides in the transverse direction of the crankshaft, and extending in the axial direction of the crankshaft, in the same direction A bearing cap holding member composed of a ladder frame (71) comprising a pair of girder members (75, 76) for joining the ends of the crosspiece members (72, 73) protruding to
The bearing cap composite of claim 6.
The bearing cap holding member according to claim 7, wherein the bearing cap holding member is made of a metal material that is lighter and has a lower melting point than the bearing cap (11).